I just bought a Hannah combo PPM/EC/PH meter (the black one). I want to start measuring my nutrients using EC. How do you use this pen for EC? It has 3 modes, PH,PPM and uS? Is this uS the same as EC? It gives you a huge number in ths mode. I thought EC should be like .2,.3.,.4...etc..
Thanks
WG
Easy peasy once you understand what the thing is telling you. That uS designation is actually microSiemens, and that's the EC reading. You have to place your own decimals, it gives the reading in whole numbers. So, for instance, let's say on the uS setting it's giving you a readout of 1510, that's an EC of 1.51.
One of the neat things about these meters is that you can set what conversion factor you want to use for ppm readings, either .5 or .7 conversion. I chose .5 just because mentally it's easier for me.
Lastly, it's very important to understand what the meter can NOT do for you, and that's measure ppm's or EC of
organic molecules, this device only gives accurate readings for chemical salt fertilizers. That means that some things, like, say... molasses, could cause your EC to look like it's going off the charts, but in reality it's right where your plants like it.
It's better to use EC because it's not only much more accurate, but it's just plain easier to use once you have your head wrapped around it. Also, it should be noted that ppm and TDS readings are *actually* calculations based on EC.
Have you figured out how to calibrate the meter? Calibration on a regular basis is extremely important or the tool becomes worse than useless to you. I always calibrate pH using the two-point method, and calibrate EC using the recommended solution, which if I recall is a NaCL (sodium chloride) solution at something like 1430 EC.
The thing with calibration is that you have to hold the left button down until it says CAL
while the pen is in the mode you wish to measure, i.e. in pH mode if you wish to calibrate pH, in EC mode if you wish to calibrate EC. If you continue to hold it down it will then flash to TEMP, if I recall.
